Percussive hammer, drill, and the like.



W. H. WAKFER,

PBROUSsIVE HAMMER, DRILL, AND THE LIKE. APPLICATION FILED FEB. 14, 1914.

1,1 14,075 Q Patented Oct. 20,1914,

'nnrirnn s rarns ra'rnnr orino "WILLIAM HENRY WAKFER, OF SOUTH NORWOOD, ENGLAND, ASSIGNOR 01* GIVE-HALF T SAMUEL PECK, OF WALLINGTON, ENGLAND.

PERCUSSIVE HAMMER,

Specification of Letters Patent.

is a specification, being a division of my ap-- plication Serial Number it, if) a.

T his invention relates to improvements in and connected with percussive hammer drills and like percussive tools.

The principal object of the prrsenit invention is to provide a simple and etiicient cornhined valve and cylinder for such tools, the cylinder and valve, including the passages ports and working parts tor giving admission exhaust and auxiliary exhaust, lJGlIlfJ, so svnnnetrically designed and arranged that the cylinder and valve can be mounted in the tiiol with either end to the front, the main and aut ziliary exhausts being led oli't through the same exhaust connection under 77% ,S' 93, filed June control of a throttle valve, the adjustn'ientoi. which controls the working of the tool by varying the back pressure.

Other objects are to provide facilities for valvular adjustments and for lubrication as will he hereinafter explained.

'In. order to enable the invention to be readily iiinderstood "etereni'se is made to the accompanying dr: mags in which Figure l is a loiigritiulinal section oi a percussive hannner drill having the present inrn-ovements applied thereto, Fig. 9, is partly a.v plan and partly a section on the line ll -l'l of Fig". l Fig. 3 is a vertical section on the line Tll -lll of Fig. 1; Fig. 4 is an elevation oi" the liner of the valve chestremoved; Fig. 5 is an end view of a throttle valve adapted to he fitted to the exhaust of the tool and his a plan of the valve seen in Fig. 5.

in the drawings rs indicates theeylinderin which the piston 7) rccipro.'-ates. The

piston shown in l igr. 1 is formed or fitted with a rod (1 at each end the forward rod being ada 'ited to act as the hammer and to strike the reduced end of the shanlc g oi a DRILL, AND THE LIKE.

Patented Oct. 1914,

Serial No. 773,993. Divided and'thisapplication filed February 14,

Serial No. 818,692.

drill or the like at the end of the forward stroke. A piston formed or fitted at each end with a rod 0 is said to be double ended but the present invention is applicable not only to such pistons but also to the usual type of single ended piston that is to say a piston having only a forwardly directed rod 0. The latter is usually lielieally formed or threaded for working in a rotation nut which engages with a drill holding sleeve or chuck (r for rotating the latter. In the ex ample shown in the drawing the not a is shown fitted with radially slidable pawls which under the action oi springs, constantly engage internal ratchet teeth formed on the ring 8 which is rigidly held between the front head 7) and the front cover ring (1 of the cylinder a. The rear end of the cylinder (L which is a counterpart of the front end is closed by a cover ring g and the rear piston rod 0 works in a rear nut e the pawls of which engage a ratchet ring, rigidly held or clamped between the rear cover ring and a cover if a piston having only a single rod 0 be used however, the rear nut e and ratchet and pawl ineehanisn'i are dispensed with and the rear end. of the cylinder may be closed by an imp'erforate cover which is substituted for the rear cover ring; The present invention however concerns the syinmetricailconstruction and arrangement of the cylinder (1, and its ports and passages and valve and before proceeding with a description of the latterit may he re marked that the cylinder is constructed with two similar ends either of which may he a rrangred toward the front for engaging with-the l'rontcoverring 1/. lo the event o an iiupcri ol'ate cover being substituted for the rear cover ring as hereinheiore indicated such eover would be made similarly to the cover rings 9 sons to [it into either end of the cylinder.

The valve chest 24: which is advantageously made in one piece with the cylinder (6 is arranged centrally oi the latter. The chest 24 comprises a central cylindrical space the axis of which is parallel with the axis of the cylinder and the ends oi' this space are closed by plugs 25 formed with axial, hollows or recesses so which connnrmieate with circumferential grooves or passages 27 in the plugs through radial holes or 130M528; The grooves 527 are formed in. such. a position on their respective plugs that they conic opposite respective. orts 29; which communicate with passages sailing-to respective ends'of the cylinder. "Longitudinal passages 30 are formed iuthc wall of the cylinder by drilling holes from the ends to a point midway along the cylinder the. outer ends of these holes being conveniently plugged by plugs 31. The ports open into the passages 30 and ports-32 0mm from the passages 30 into the ends of the cylinder.

A tubular liner 33 is inserted into the ccntral cylindrical space in the chest and is kept in the desired position by the plugs which are screwed. home against the liner As will be apparent from Fig. l, the plugs are of such a length that either may be screwed in While the other is screwed out so that the liner may receive cndwisc adjustment which in some cases iuav be very advantageous as hereinafter explained.

The piston. slide alve 34, is capable of free movement to and fro Within the liner 33, its motion being arrested in either directicn by the annular ends of the hollow plugs 25, which form seats for the respective end faces of the piston valve El i. Each end of the piston valve 34 may be hollowedout centraliy and. for a distance axially as at 35, the hollow spaces in the valve and the plugs having the eii'ect of cushioning the valve at the moment of seating. The external diimr eter oi the end portions of the valve may be reduced as seen in 2 so that an annular and reduced of the valve strikes and seats against a corresponding plug at each end oft-he travel of the valve.

The admission 36 Fig. 3 for the pressure fluid or power medium is suitably at one side of. the chest and the liner has preferably two sets of ports 37, 37 Figs. 3 and 4*. on that side adapted to be alternately covered and uncovered by the cylindrical body of thevalve in its reciprocni'ory movements. The exhaust connection 38 is conveniently at the other I side of the chest immediately opposite the admission 36 and inclined ports or passages I 39 are bored or formed from the mam exhaust 38 to points situated near to the -:mid Way point in the length of the cylinder, as will. be readily understood by reference to Fig. 1 so that the piston o uncovers one or other of such exhaust ports 39 or sets there of, us it nears the completion of each stroke.

As seen in Fig. 3, the exhaust ports 39, 39,

space 26, radial passages 28 and groove 27 in the rear plug 25 and through the rear passages 29 and and rear port 32 in thd cylinder has driven the piston 6 forward. Dor inr; the forward stroke of the piston 12 the valve 34 has been held against its seat on the right hand plug 25 by the pressure fluid acting on the left hand or rear end of the valve but as the piston reaches the end of its stroke it uncovers the rear exhaust port 39. In Fig. l the piston has fully uncovered this port. The pressure behind the piston and to the left hand of the piston valve 34, is suddenly lowered as the piston b uncovers this port 39 and the back pressure or cushioning pressure in front of the'piston Z) and to the right hand of the valve 34: immediately acts upon the latter and quickly moves the valve 341 s gainst the seat on the left hand plug thereoy admitting pressure fluid to the forward end of the cylinder and cutting it off from the rear end, 'lhereupon the piston Z. is driven rearwardly' and immediately covers the rear exhaust port 39 and upon the forward exhaust port 39 being uncovered near the end of thercaru'ard stroke a reversal will take place similar to that just described and the cycle of operations will be repeated so long as pressure fluid is admitted at 36, the Working of the tool being controlled by checking or throttling the exhaust by a throttle valve on the exhaust pipe.

It has been explained. how the exhaust port or ports on one side is or are cov-- ered by the piston soon after the latter has reversed and commenced. a stroke in, the opposits direction. Now in order to prevent I the pressure fluid which has not had time to escape to the'cxhaust from setting up a considerable back oressuzv auxiliary exhaust ports 40 are formed say at the inner ends of the longitudinal passages 30. These ports 40' may be comparatively small and ar adopted to be alternately covered and" um covered by a groove or cavity 41 in the valve 34 which cavity 41 places the appropriate one of these auxiliary ports in communication with an exhaust port or ports 4% formed in the liner 33 about midway between the ends of the latter as seen clearly in Fig. 2. The ort 420 and the sets of ad mission ports are so rclati vely disposed that the valve 8% can never open a through way from the-admission so to the exhaust 38. As seen in Fig. 1 the outlet of the ports or passages 40 may be made of any desired size by forming suitable holes all) in the liner In this figure, the val vs 34 is shown in the position for relieving the back pressure in the forward end of the cylinder (1, it being assumed as stated that the piston in finish- .the holes 42 may be moved Wholly or partly exhaust as found desirable (inconvenient.

lly attaching an exhaust pipe to the connection 38 and by having a throttle valve in said pipe the working of the tool may he effectually controlled by opening or closing the throttle on the exhaust and varying the l'mclr pressure The check exhaust or't-hrottle valve seen. 1. l7 n 1n Jigs. o and n "which is formed very advantageous, and may be fitted in the connectioirllll, coin 'n'iscs a hexagonalbody 49 having screw threaded portions 50 at its two ends and adisk valve 51 pivotally mounted Within its here. The valve 51 is mounted upon the square portion of the SP'lIllll? 52 which may slide in the diametrical sleeve portion or hole in the valve disk.

'lhe spindle is normally depressed by say a spring which keeps the lower pivotal portion 54 of the spindle 52 in its hearing and the handle 55 on the upper end of the sp1n-.

dle in engagement with serrations, notches, or projections 560 arranged on the body 49 in. a partcircular series in known manner. The valve 51 may be opened or closed grad-- ually after raising the handle against the action of the spring 53 and the projections not only afford an indication of the degree of opening or closing of the valve but, when the handle 55 is released, interlock With the said handle 55 and maintain the valve in its adjusted position. The spindle 52 may be suitably formed or packed to prevent escape otthe fluid as will be readily understood.

It may be desirable to fit a lubricator to the valve chest ill and this is conveniently accomplished by screwing an oil. cap ll, to the chest on the top or outer side of the latter. 'The spigot portion ll of the cup=1nay be tilled by a plug 45 having suitable pertorations 46 adapted to come opposite perform tions; 4? in the liner 33%,thc last named perforations hcing in such a position that they can never be uncovered by the valve 34 at the same time the valve uncovers the ad mission ports. fl dowel or device 48 Fig. 3 may he formed on the plug 45 and may be adapted to reach and enter a longitudinal slot or groove l'oru'icd in the liner 33. In this way the liner is prevented tronrturning or loving laterally while it is capable of end wise or longitudinal adjustment under the action of the screvv plugs in the manner hercinlmfore described.

It will he noted that all the ports and pas- SllfIOS are symmetrically constructed and arranund so that the api'iaratus Works equally well and in an identical manner no i'uatter which cud is toward the front.

l cla m: l. A percussive tqol comprising a cyl1nranged near the snuslido valve in the valve cheat adapled to control admission oi? pressure fluid to and exhaust from the two sides of said piston, a

liner in the chest for said slide valve, and hollow ported plugs secured in the valve chest and :t'orn'ung seats for respective ends of said valve and adapted to adjust said liner, the slide alve being formed with a cavity arranged to open one or the other of two auxiliary exhaust ports to the exhaust passage.

A percussive tool, comprising a cylinder reversible end for end, a piston haminer in said cylinder, a valve chest connected with the.cyl.inder, a piston slide valve in the valve chest adapted to control admission of pressure fluid to and exhaust from. the two sides of said piston, a liner in the valve chest for lie slide valve. and hollow ported pli'igs in the valve chest forininq seats for respective ends of said valve and a apted to adjust said liner, the piston valve being formed between its ends with. a cavity which is adapted to open one or the other of two auxiliary exhaust ports to the exhaust -passage zsaid auxiliary exhaust ports being ar iddle of the cylinder at the inner ends of passages extending from ports at lIQSPCCtlVG ends of the cylinder.

4-. A percussive tool, comprising a cylinder rover lo and for end, a piston hammer in said cylinder, a valve chest connected with. the cylinder, a piston slide v-'lve in said chest adapted to control admission of pres sure fluid to and exhaust from the two sides of said piston, hollow ported plugs secured in the ends ot the valve chest and adapted to act seats for respective ends of said valve, each of said plugs being formed with ports communicating with the hollow space of the respective plug, said valve being formed between its ends with a cavity adapted. to uncover in alternation. two auxiliary e11:- hausts, the ports and passages ct which are sj 'rnnictrically fru'med in said ("linden Said auxiliary exhausts connnuuic: n; with the main exhaust whenuncovered hy said. valve, and a throttle valve on the common exhaust connection.

A percussive tool, comprising a cylinder, a piston hammer in said cylinder, 21. valve chest, a, piston slide valve in the latter adapted to control admission of pressure fluid to and exhaust from the lJWO sides of valve chest connected with the cylin T said ,jpistgm, liner in the valve shasi: for spigot; portion inclosing lubricant passages, s'siid waive, lwilow ported plugs s'acu ad in adapted to communicate Withlubriczmt part-s Said valve and formmg seats; 01 my in said liner.

spe'c'tive entls of said valve and. adapted to YVILLKAM HEN Y WAKIHER" adjust said liner; and a lubricant receptach Witnessms:

cagmprising a spigot portion adapted to be 331mm; Wison,

secured in an ayer'bm'e in said" ehest, saidi P. PHIDLIPS. 

